Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
Institute of Neuroscience, University of Oregon, Eugene, OR, 97403, USA.
Sci Rep. 2020 Jun 22;10(1):10047. doi: 10.1038/s41598-020-66862-5.
Parvalbumin (PV)-expressing interneurons (PV-INs) mediate well-timed inhibition of cortical principal neurons, and plasticity of these interneurons is involved in map remodeling of primary sensory cortices during critical periods of development. To assess whether bone morphogenetic protein (BMP) signaling contributes to the developmental acquisition of the synapse- and plasticity properties of PV-INs, we investigated conditional/conventional double KO mice of BMP-receptor 1a (BMPR1a; targeted to PV-INs) and 1b (BMPR1a/1b (c)DKO mice). We report that spike-timing dependent LTP at the synapse between PV-INs and principal neurons of layer 4 in the auditory cortex was absent, concomitant with a decreased paired-pulse ratio (PPR). On the other hand, baseline synaptic transmission at this connection, and action potential (AP) firing rates of PV-INs were unchanged. To explore possible gene expression targets of BMP signaling, we measured the mRNA levels of the BDNF receptor TrkB and of P/Q-type Ca channel α-subunits, but did not detect expression changes of the corresponding genes in PV-INs of BMPR1a/1b (c)DKO mice. Our study suggests that BMP-signaling in PV-INs during and shortly after the critical period is necessary for the expression of LTP at PV-IN output synapses, involving gene expression programs that need to be addressed in future work.
钙结合蛋白（PV）表达中间神经元（PV-INs）介导皮质主要神经元的适时抑制，这些中间神经元的可塑性参与了发育关键期初级感觉皮层图重构。为了评估骨形态发生蛋白（BMP）信号是否有助于 PV-INs 的突触和可塑性特性的发育获得，我们研究了 BMP 受体 1a（BMPR1a；靶向 PV-INs）和 1b（BMPR1a/1b（c）双敲除（DKO）小鼠的条件/常规双敲除。我们报告说，在听觉皮层第 4 层 PV-INs 和主神经元之间的突触上，依赖于尖峰时间的长时程增强（LTP）缺失，同时伴随着成对脉冲比（PPR）降低。另一方面，这种连接的基础突触传递和 PV-INs 的动作电位（AP）放电率保持不变。为了探索 BMP 信号的可能基因表达靶标，我们测量了 BDNF 受体 TrkB 和 P/Q 型钙通道 α 亚基的 mRNA 水平，但未检测到 BMPR1a/1b（c）DKO 小鼠中 PV-INs 相应基因的表达变化。我们的研究表明，发育关键期内和之后不久，PV-INs 中的 BMP 信号对于 PV-IN 输出突触的 LTP 表达是必需的，涉及到未来工作中需要解决的基因表达程序。
